1. Field of the Disclosure
This disclosure relates generally to drill bits and systems that utilize same for drilling wellbores.
2. Background of the Art
Oil wells (also referred to as “wellbores” or “boreholes”) are drilled with a drill string that includes a tubular member having a drilling assembly (also referred to as the “bottomhole assembly” or “BHA”). The BHA typically includes devices and sensors that provide information relating to a variety of parameters relating to the drilling operations (“drilling parameters”), behavior of the BHA (“BHA parameters”) and parameters relating to the formation surrounding the wellbore (“formation parameters”). A drill bit attached to the bottom end of the BHA is rotated by rotating the drill string and/or by a drilling motor (also referred to as a “mud motor”) in the BHA to disintegrate the rock formation to drill the wellbore. The drill bit is subjected to great mechanical stresses during drilling of a wellbore. Some drill bits, such as roller cone drill bits and hybrid drill bits, include a bearing seal between a non-rotating member and each rotating cone that contains cutters on the roller cones. During drilling, the load on the cones continuously changes due to, among other things, the change in the rotational speed of the drill bit, the nature of the formation, etc.
A function of a bearing seal in a drill bit is to protect the bearing by inhibiting the ingress of drilling fluid and solid and to seal the grease used to lubricate both the bearing and the seal. There are two main seal types: elastomeric seal and metal face seal; both contain elastomeric components which seal and energize the sealing face. The seal components usually are made of elastomer compound formulated for the drilling environment. In geothermal drilling, the temperature in the well can rise above 300° C. and cause thermal degradation of elastomeric compounds used in the seals, resulting in bearing and thus premature drill bit failure.
The disclosure herein provides a metallic seal that addresses some of the above-noted issues.